Elevator car safety device



Aug. 23, 1932. J. DUNLQP ELEVATOR CAR SAFETY DEVICE Filed Aug. 8, 1930INVENTOR James Dun/op TTO'RNEY Patented Aug. 23, 1932 UNITED S ATESDUNLor, F PARK RIDGE, ILLINOIS, ASSIGNOR To wEsirInGrIo sE ELEoTBIo &

JAMES ATENT oFF cE v MANUFACTURING COMPANY, A CORPORATION GFBENNSYLVAHIA ELEVATOR CAR SAFETY'DEVICE Application filed August a,1930. 7 Serial No. 473,915

My invention pertains to safety devices for elevators and morespecifically to means for setting car safety devices even though thegovernor cable breaks when the governor jaws set. Y

In a very high-rise elevator installation, the weight of the'governorcable is sufficient to place a considerable strain upon itself.-

In such installations, theadditional strain 10 placed upon the cable,when the governor gripped by the governor jaws, the-safety de vice, maybe suflicient to cause the rupture thereof. If the cable breaks when itis vice will not be applied in such systems since it is the pull on thegovernor cable effected by the cable-gripping jaws which unreels thesafety cable and sets the safetydevice.

It is, accordingly, also an object of my invention to provide meanswhich, when actuated, will apply the car-safety device independently ofthe governor cable.

A further object of my invention is to provide means which, having beenactuated by a preliminary tensioning of the governor cable, will applythe usual car-safety device independently of the continuation of thetensioned condition of the cable.

In accordance with my invention, I will provide a small roll-catchdevice which is associated with the governor cable and releasablycarried by the car. A safety actuator cable is connected betweenthecar-safety device and the roll-catch device. In the event of breakageof the cable, the roll catch will lock itself to the guide rail, and thecontinued downward movement of the car will pull the safety actuatorcable taut and apply the car safety device.

The invention itself, however, both as to its organization and itsmethod of operation, together with additional objects and advantagesthereof, will best be understood from the following description of aspecific embodiment, when read in conjunction with the accompanyingdrawing in which:

Figure 1 is a diagrammatic view of an elevator system provided withasafety operat; ing device in accordance with my invention,

aws grip it in applying the car-safety de- Fig. 2 is anenlargedsectional view, takenon line II'II of Fig. 1, and;

Fig. 3 is an enlarged sectional view of the minnie ball.

The apparatus shown in Fig. 1 comprises an elevator car C supportedbyhoist cables Gain a well known manner. The hoist cables sheave l2at thetop of the hatchway and underan idler sheave 13 at the bottom of thehatchway. The governor cable 11 carries a minnie ball 14, the details ofwhich are shown 'in Fig. 3. 'A bracket 16, of any suitable shape, may bemounted on the car G to support a-releasable spring clip 18. The springclip 18 normally holds the minnie, ball 14 with sufficient tension topull the associated governor. cable up and down the hatchway inaccordance with the movements of the elevator car.

Associated with the sheave 12 is a governor 20 which is driven therebyat speeds proportional to the speed of the elevator car as it passes upand down the shaft. A pair of cable-gripping 2-1 and 22 arepivotallymounted on opposite sides of the governor cable 11 where itpassesfrom'one side of the sheave 12. The jaws are provided'withcamformed cable-gripping surfaces which will grip and lock; the adjacentcable if turned into contact therewith when it is moving downward.Through a pivoted lever 23 and a link member 24, the governor 20 mayactuate the cable-gripping jaws 21 and 22 to gripping position when theelevator car moves at a predetermined excessive speed-{1 The spe cificgovernoncable-gripping j aws, actuating mechanism and sheave used areimmaterial andinay be any specific structure well known intheart. x v Acar-safety braking device30, carried by in any suitable manner.

the car C, comprises any well known carsafety device of the type havinga cable drum and jaws 31 actuated by unreeling the cable for grippingthe guide rails and applying a braking force to retard the car when asafety cable 32 is unreeled from the safety drum. The structural detailsof the safety device are not shown since any well known safety devicemay be used, such for example as that disclosed in my prior patent No.1,598,065.

Ordinarily, the safety actuating cable 32 would be connected directly tothe governor cable 11 by the minnie ball 14,'whereby the downwardmovement of the car, after the cable 11 is locked by the jaws 21 and 22,would unreel the cable 32 from the safety drum and apply the safetydevice. This method of operating the safety device places an additionalstrain on the governor cable 11 which may be suflicient. to break thatcable in highrise installations where the weight of the cable is itselfsuificient to cause considerable strain at all times. It will beapparent that, when the governor cable breaks in such systems, the carsafety device'will not be applied.

In accordance with my invention, a small roll catch 35 is connected tothe safety actuating cable 32, and the roll 36 thereof is connected, bya bail 37 and a cable 38, to the governor cable 11, as clearly shown inFig. 2. The roll 36 may be of hardened steel provided with a knurledsurface that will bite into the surface of the guide rail 2 when liftedinto contact therewith by the cable 38. The roll is received by a recess39 in the body of the device 35 where it normally rests in spacedrelation from the web of the guide rail 2, as shown in Fig. 2. The uppersurface of the recess 39 is inclined toward the rail in such manner thatthe roll will be forced into contact with the rail when it is lifted.The in clination of the upper surface of the recess 39 toward the rail 2is also effective to force the roll 36 into closer engagement with theguide rail, as the car continues downward.

The roll-catch device 35 is releasably mounted on the car C above theguide shoe A As shown in Fig. 1, the roll-catch device 35 is supportedon a bracket 41 that is slidably received by the bracket '7 whichsupports the guide shoe 4.

In Fig. 3, I have shown the specific structure of the minnie ball 14which is carried by the governor cable 11 for detachably securing thelatter to the spring clip 18. The minnie ball comprises two halvesbolted together. As shown in Fig. 3, the inner surface of one half ofthe minnie ball is ex posed, the other half thereof having been removed.The inner surface of each half of the ball is provided with a groovewhich receives the cable 11. A second groove is provided for receivingthe cable 38. In order to increase the friction of contact of the cablewith the minnie ball, the grooves may be curved from side to side ratherthan straight. The second half of the minnie ball is provided withidentical grooves, and, when the two parts of the ball are boltedtogether, the cables will be clamped into the grooves. The minnie ball14 serves not only as a button tobe releasably received in the springclip 18 but also as a clamp for attaching cable 38 to cable 11.

My invention is best understood, however, when considered with referenceto an assumed operation thereof. Assuming, for example, that the car,when traveling down the hatchway, attains an objectionable degree ofoverspeed, the governor 20 will actuate the jaws 21 and 22 tocable-gripping position. The jaws will grip the cable 11 with suflicientforce to pull the minnie ball 14: from the spring clip 18, and thecontinued downward motion of the car will draw the cable 38 taut,thereby lifting the roll 36 into engagement with the guide rail 2. Asthe roll 36 bites into the rail 2, the continued downward movement ofthe car will cause the inclined upper surface of the recess 39 to forcethe roll into closer engagement with the rail until the roll-catchdevice 35 grips the rail with sufiicient force to pull away from thebracket 7 by which it was releasably mounted on the car. The roll-catchdevice 35 will continue to grip the rail 2, even though the governorcable 11 becomes ruptured. Since one end of the cable 32 is attached tothe roll-catch device 35, the downward movement of the car will thencause the cable 32 to be unreeled from the cable drum of safety device30, thereby setting the car safety jaws 31 to grip the guide rails andstop the car.

It will be seen, therefore, that I have provided a safety actuatingdevice for elevators wherein the downward motion of the car itself isutilized to unreel the safety cable and set the safety device,irrespective of the condition of the governor cable after it has beengripped by the governor jaws to initiate the operation of the device.

Although I have shown and described certain specific embodiments of myinvention, I am fully aware that many modifications thereof arepossible. My invention, therefore, is not to be restricted exceptinsofar as is necessitated by the prior art and by the spirit of theappended claims.

I claim as my invention 1. In combination, an elevator car, a safety 1ibraking device for retarding the car, means operably responsive to apredetermined speed of the car, actuating means operated thereby forapplying said safety braking device to retard the car in the eventthatthe speed thereof becomes excessive, and means mounts ed detachably onthe car for separating therefrom and completing the application of saidsafety device, said means being responsive to an initial operation ofsaid speedresponsive device even though the initial actuating force isnot maintained.

3. In combination, an elevator car, a safety braking device forretarding the car, speedresponsive means operable at speedscorresponding to the speed of the car, actuating means operable therebyat apredetermined speed of the car for rendering the movement of the careffective for applying said safety braking device to retard the car inthe event that the speed thereof becomes excessive, and additionalactuating means whereby the continued movement of the car is renderedeffective to complete the application of the car safety device eventhough the first actuating means becomes inoperative after its initialoperation.

4:. In combination with an elevator system comprising an elevator caroperable up and down a hatchway between guide rails, a safety brakingdevice carried by the car and actuable by unreeling a cable for grippingthe guide rails to stop the car, an overspeed governor, a cableassociated therewith for actuating said safety device when the cartravels at an excessive speed, and means mounted detachably on the carfor completing the application of the safety device even if the governorcable is ruptured by the initial operation thereof.

5. In combination with an elevator system comprising an elevator caroperable up and down a hatchway between guide rails, a safety brakingdevice carried by the car for gripping the guide rails to stop the car,a safety actuating cable, an overspeed governor and cable associatedtherewith for actuating said safety device when the car travels at anexcessive I speed, and means for completing the application of thesafety device even if the governor cable is ruptured by the initialoperation, said means comprising means for clamping the safety actuatingcable to the guide rail.

6. In combination with an elevator system comprising an elevator caroperable up and down a hatchway between guide rails, a'safety breakingdevice carried by the car for gripping the guide rails to stop the car,a safety actuating cable associated with the safety device, a roll-catchdevice connected to said safety actuating cable and detachably mountedon the car in position for clamping the guide rail when actuated, aspeed-responsive device operable in accordance with the speed of thecar, and actuating means controlled thereby at a predetermined car speedfor operating the roll-catch device to clamp the safety cable to theguide rail, whereby continued movement of the elevator car will actuatethe car-safety device.

7 A safety mechanism for an elevator car operable between guide railscomprising a common safety braking device for gripping the guide railsto stop the car, an overspeed governor, a cable associated therewith foractuating said safety device when the car travels at an excessive speed,and means comprising a roll catch device separate from the safety devicefor completing the application of the safety device even if the governorcable is ruptured by the initial operation thereof.

In testimony whereof, I have hereunto subscribed my name this31st day.of July, 1930. JAMES DUNLOP.

